Drug-Induced Fatty Liver Disease (DIFLD): A Comprehensive Analysis of Clinical, Biochemical, and Histopathological Data for Mechanisms Identification and Consistency with Current Adverse Outcome Pathways

Drug induced fatty liver disease (DIFLD) is a form of drug-induced liver injury (DILI), which can also be included in the more general metabolic dysfunction-associated steatotic liver disease (MASLD), which specifically refers to the accumulation of fat in the liver unrelated to alcohol intake. A bi-directional relationship between DILI and MASLD is likely to exist: while certain drugs can cause MASLD by acting as pro-steatogenic factors, MASLD may make hepatocytes more vulnerable to drugs. Having a pre-existing MASLD significantly heightens the likelihood of experiencing DILI from certain medications. Thus, the prevalence of steatosis within DILI may be biased by pre-existing MASLD, and it can be concluded that the genuine true incidence of DIFLD in the general population remains unknown. In certain individuals, drug-induced steatosis is often accompanied by concomitant injury mechanisms such as oxidative stress, cell death, and inflammation, which leads to the development of drug-induced steatohepatitis (DISH). DISH is much more severe from the clinical point of view, has worse prognosis and outcome, and resembles MASH (metabolic-associated steatohepatitis), as it is associated with inflammation and sometimes with fibrosis. A literature review of clinical case reports allowed us to examine and evaluate the clinical features of DIFLD and their association with specific drugs, enabling us to propose a classification of DIFLD drugs based on clinical outcomes and pathological severity: Group 1, drugs with low intrinsic toxicity (e.g., ibuprofen, naproxen, acetaminophen, irinotecan, methotrexate, and tamoxifen), but expected to promote/aggravate steatosis in patients with pre-existing MASLD; Group 2, drugs associated with steatosis and only occasionally with steatohepatitis (e.g., amiodarone, valproic acid, and tetracycline); and Group 3, drugs with a great tendency to transit to steatohepatitis and further to fibrosis. Different mechanisms may be in play when identifying drug mode of action: (1) inhibition of mitochondrial fatty acid β-oxidation; (2) inhibition of fatty acid transport across mitochondrial membranes; (3) increased de novo lipid synthesis; (4) reduction in lipid export by the inhibition of microsomal triglyceride transfer protein; (5) induction of mitochondrial permeability transition pore opening; (6) dissipation of the mitochondrial transmembrane potential; (7) impairment of the mitochondrial respiratory chain/oxidative phosphorylation; (8) mitochondrial DNA damage, degradation and depletion; and (9) nuclear receptors (NRs)/transcriptomic alterations. Currently, the majority of, if not all, adverse outcome pathways (AOPs) for steatosis in AOP-Wiki highlight the interaction with NRs or transcription factors as the key molecular initiating event (MIE). This perspective suggests that chemical-induced steatosis typically results from the interplay between a chemical and a NR or transcription factors, implying that this interaction represents the primary and pivotal MIE. However, upon conducting this exhaustive literature review, it became evident that the current AOPs tend to overly emphasize this interaction as the sole MIE. Some studies indeed support the involvement of NRs in steatosis, but others demonstrate that such NR interactions alone do not necessarily lead to steatosis. This view, ignoring other mitochondrial-related injury mechanisms, falls short in encapsulating the intricate biological mechanisms involved in chemically induced liver steatosis, necessitating their consideration as part of the AOP's map road as well.

Novel clinical phenotypes, drug categorization, and outcome prediction in drug-induced cholestasis: Analysis of a database of 432 patients developed by literature review and machine learning support

BACKGROUND

Serum transaminases, alkaline phosphatase and bilirubin are common parameters used for DILI diagnosis, classification, and prognosis. However, the relevance of clinical examination, histopathology and drug chemical properties have not been fully investigated. As cholestasis is a frequent and complex DILI manifestation, our goal was to investigate the relevance of clinical features and drug properties to stratify drug-induced cholestasis (DIC) patients, and to develop a prognosis model to identify patients at risk and high-concern drugs.

METHODS

DIC-related articles were searched by keywords and Boolean operators in seven databases. Relevant articles were uploaded onto Sysrev, a machine-learning based platform for article review and data extraction. Demographic, clinical, biochemical, and liver histopathological data were collected. Drug properties were obtained from databases or QSAR modelling. Statistical analyses and logistic regressions were performed.

RESULTS

Data from 432 DIC patients associated with 52 drugs were collected. Fibrosis strongly associated with fatality, whereas canalicular paucity and ALP associated with chronicity. Drugs causing cholestasis clustered in three major groups. The pure cholestatic pattern divided into two subphenotypes with differences in prognosis, canalicular paucity, fibrosis, ALP and bilirubin. A predictive model of DIC outcome based on non-invasive parameters and drug properties was developed. Results demonstrate that physicochemical (pKa-a) and pharmacokinetic (bioavailability, CYP2C9) attributes impinged on the DIC phenotype and allowed the identification of high-concern drugs.

CONCLUSIONS

We identified novel associations among DIC manifestations and disclosed novel DIC subphenotypes with specific clinical and chemical traits. The developed predictive DIC outcome model could facilitate DIC prognosis in clinical practice and drug categorization.

A quantitative weight-of-evidence method for confidence assessment of adverse outcome pathway networks: A case study on chemical-induced liver steatosis

The field of chemical toxicity testing is undergoing a transition to overcome the limitations of in vivo experiments. This evolution involves implementing innovative non-animal approaches to improve predictability and provide a more precise understanding of toxicity mechanisms. Adverse outcome pathway (AOP) networks are pivotal in organizing existing mechanistic knowledge related to toxicological processes. However, these AOP networks are dynamic and require regular updates to incorporate the latest data. Regulatory challenges also persist due to concerns about the reliability of the information they offer. This study introduces a generic Weight-of-Evidence (WoE) scoring method, aligned with the tailored Bradford-Hill criteria, to quantitatively assess the confidence levels in key event relationships (KERs) within AOP networks. We use the previously published AOP network on chemical-induced liver steatosis, a prevalent form of human liver injury, as a case study. Initially, the existing AOP network is optimized with the latest scientific information extracted from PubMed using the free SysRev platform for artificial intelligence (AI)-based abstract inclusion and standardized data collection. The resulting optimized AOP network, constructed using Cytoscape, visually represents confidence levels through node size (key event, KE) and edge thickness (KERs). Additionally, a Shiny application is developed to facilitate user interaction with the dataset, promoting future updates. Our analysis of 173 research papers yielded 100 unique KEs and 221 KERs among which 72 KEs and 170 KERs, respectively, have not been previously documented in the prior AOP network or AOP-wiki. Notably, modifications in de novo lipogenesis, fatty acid uptake and mitochondrial beta-oxidation, leading to lipid accumulation and liver steatosis, garnered the highest KER confidence scores. In conclusion, our study delivers a generic methodology for developing and assessing AOP networks. The quantitative WoE scoring method facilitates in determining the level of support for KERs within the optimized AOP network, offering valuable insights into its utility in both scientific research and regulatory contexts. KERs supported by robust evidence represent promising candidates for inclusion in an in vitro test battery for reliably predicting chemical-induced liver steatosis within regulatory frameworks.

P-356 Clinical implications of first-trimester ultrasound dating in singleton pregnancies obtained through in vitro fertilization

Study question

Is there a correspondence between ultrasound estimation of gestational age (GAUS) and its calculation based on embryo transfer date (GAIVF), in in-vitro fertilization (IVF) pregnancies?

Summary answer

GAUS and GAIVF are not overlapping, being the first mildly greater than the latter, maybe due to anticipated ovulation and fertilization or accelerated embryo development.

What is known already

In IVF pregnancies the precise date of conception is known. However, it is possible that some factors (such as a time delay between conception and implantation, an early in-vitro embryo development, and the maternal environment itself with its altered hormonal milieu) may influence the early stages of embryonic development. Data regarding first-trimester fetal development in IVF pregnancies are in fact conflicting and both underestimation and overestimation of the true GA were reported when traditional charts were used for ultrasound pregnancy dating.

Study design, size, duration

A retrospective study was performed, including all singleton IVF pregnancies who underwent the first-trimester ultrasound scan for the screening of aneuploidies between January 2014 and June 2019. For each pregnancy GA was determined using two alternative methods: one based on the date of embryo transfer (GAIVF), and one based on ultrasound measurement of crown-rump length (CRL) (GAUS). GA were compared to search for any discrepancy. The impact of pregnancy dating on obstetric outcome was evaluated.

Participants/materials, setting, methods

All women with singleton pregnancies conceived by conventional IVF or intracytoplasmic sperm injection (ICSI), who performed first-trimester ultrasound scan for the screening of aneuploidies at the Department of Obstetrics and Gynecology ‘L. Mangiagalli', Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, were included. Exclusion criteria were as follows: multiple pregnancy (i.e., the evidence of more than one gestational sac at the first ultrasound scan), abnormal karyotype and/or congenital malformations detected either in pre- or postnatal period.

Main results and the role of chance

Overall, 249 women were selected: 111 pregnancies (45%) by conventional IVF, and 138 (55%) by ICSI. Among the included women, 127 (51%) pregnancies resulted from frozen-thawed embryo transfer. At first trimester ultrasound scan, the discrepancy in days between GAUS and GAIVF was ≥ 4 days in 32 cases (13%, 95%CI: 9-18%). It ranged within 2 and 3 days in 100 cases (40%, 95%CI: 34-47%). In 117 cases (47%, 95%CI: 41-53%) GAUS and GAIVF overlapped or showed a discrepancy of ± 1 day. Comparing GAUS and GAIVF at first trimester ultrasound scan, the median values of GA were 88 [86 - 91] days and 87 [85 - 90] days, respectively (p < 0.001). The median difference was 1 [0 - 2] days, with GAUS systematically higher than GAIVF. This discrepancy persisted when subgroups were analyzed comparing different IVF procedures (conventional IVF versus ICSI, cleavage versus blastocyst transfer, frozen versus fresh transfer). The overall duration of pregnancy differed, with median values of 274 [269 - 281] days in GAUS group and 273 [268 - 280] days in GAIVF group, (p > 0.001). No impact of the dating method on obstetric outcomes was observed, being no differences in the rate of preterm birth or abnormal fetal growth.

Limitations, reasons for caution

This is a retrospective study and thus exposed to the inaccuracies of this study design. Moreover, being a single-centre study, the sample size is relatively small. Finally, ultrasound evaluations were performed by multiple operators: although they are all certified, there is some inter-individual variability that may impact on the results.

Wider implications of the findings

Despite a known date of conception, it is difficult to assume that the oocyte retrieval date precisely resembles the date of natural ovulation and conception. IVF seems to anticipate fertilization. On these bases, it would be advisable to date IVF pregnancies using GAUS to realign them to natural pregnancies.

Trial registration number

Not Applicable

Defined D-hexapeptides bind CUG repeats and rescue phenotypes of myotonic dystrophy myotubes in a Drosophila model of the disease

In Myotonic Dystrophy type 1 (DM1), a non-coding CTG repeats rare expansion disease; toxic double-stranded RNA hairpins sequester the RNA-binding proteins Muscleblind-like 1 and 2 (MBNL1 and 2) and trigger other DM1-related pathogenesis pathway defects. In this paper, we characterize four d-amino acid hexapeptides identified together with abp1, a peptide previously shown to stabilize CUG RNA in its single-stranded conformation. With the generalized sequence cpy(a/t)(q/w)e, these related peptides improved three MBNL-regulated exon inclusions in DM1-derived cells. Subsequent experiments showed that these compounds generally increased the relative expression of MBNL1 and its nuclear-cytoplasmic distribution, reduced hyperactivated autophagy, and increased the percentage of differentiated (Desmin-positive) cells in vitro. All peptides rescued atrophy of indirect flight muscles in a Drosophila model of the disease, and partially rescued muscle function according to climbing and flight tests. Investigation of their mechanism of action supports that all four compounds can bind to CUG repeats with slightly different association constant, but binding did not strongly influence the secondary structure of the toxic RNA in contrast to abp1. Finally, molecular modeling suggests a detailed view of the interactions of peptide-CUG RNA complexes useful in the chemical optimization of compounds.

Author Correction: A novel methodology for epidemic risk assessment of COVID-19 outbreak

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A novel methodology for epidemic risk assessment of COVID-19 outbreak

We propose a novel data-driven framework for assessing the a-priori epidemic risk of a geographical area and for identifying high-risk areas within a country. Our risk index is evaluated as a function of three different components: the hazard of the disease, the exposure of the area and the vulnerability of its inhabitants. As an application, we discuss the case of COVID-19 outbreak in Italy. We characterize each of the twenty Italian regions by using available historical data on air pollution, human mobility, winter temperature, housing concentration, health care density, population size and age. We find that the epidemic risk is higher in some of the Northern regions with respect to Central and Southern Italy. The corresponding risk index shows correlations with the available official data on the number of infected individuals, patients in intensive care and deceased patients, and can help explaining why regions such as Lombardia, Emilia-Romagna, Piemonte and Veneto have suffered much more than the rest of the country. Although the COVID-19 outbreak started in both North (Lombardia) and Central Italy (Lazio) almost at the same time, when the first cases were officially certified at the beginning of 2020, the disease has spread faster and with heavier consequences in regions with higher epidemic risk. Our framework can be extended and tested on other epidemic data, such as those on seasonal flu, and applied to other countries. We also present a policy model connected with our methodology, which might help policy-makers to take informed decisions.

Parietal interhemispheric transfalcine transtentorial approach for posterior incisural space lesions: from the lab to the operative room

The operative approach to the posterior incisural space is challenging because of its deep location, the surrounding eloquent areas, and the intimate relationship with the deep veins. Several approaches have been proposed to manage the lesions in this region: supratentorial, infratentorial and a combination of them. Brain retraction, injury to the occipital lobe and corpus callosum, and venous bleeding are the principle drawbacks of these routes. We performed anatomical dissection study using 10 embalmed human cadaver specimens injected with colored latex exploring a different route, parietal interhemispheric transfalcine transtentorial (PITT). Then we used a PITT approach on two patients with posterior incisural space (PIS) lesions. The PITT approach led to successful and safe complete removal of PIS lesions in our cases. No complications were reported. The present approach could be a valuable option in case of PIS lesions, especially those associated with downward displacement of the deep venous complex; thanks to the gravity it reduce the complications related to the occipital lobe retraction and manipulation. Moreover, cutting the superior-anterior edge of the tentorium, the sub-tentorial space could be reached.

The relationship between negative symptom subdomains and cognition

BACKGROUND

Negative symptoms and cognitive deficits in schizophrenia are partially overlapping. However, the nature of the relationship between negative symptoms and cognition remains equivocal. Recent reviews have demonstrated the presence of two negative symptom subdomains, diminished emotional expression (DEE) and avolition. In view of this, we sought to clarify the relationship between negative symptoms and cognitive domains.

METHOD

A total of 687 participants with schizophrenia were assessed on measures of psychopathology and cognition. Three cognitive factors, namely executive function, fluency/memory and speed/vigilance were computed from the cognitive tests. Confirmatory factor analysis was utilized to examine if a one-factor or two-factor negative model was applicable to our sample. Subsequently, the relationships between negative symptoms and cognition were examined using structural equation modeling.

RESULTS

Results demonstrated that the two-factor model fitted the data well. While negative symptoms were mildly to moderately associated with cognition, we found that DEE had unique associations with cognition compared to social avolition, contributing to the validity of the constructs and suggesting the possibility of common underlying substrates in negative symptoms and cognition.

CONCLUSIONS

Our study highlighted the need to classify DEE and social avolition separately as both are necessary in refining the complex relationship between negative symptoms and cognition as well as potentially guiding treatment and management of schizophrenia.

Refining the latent structure of neuropsychological performance in schizophrenia

BACKGROUND

Elucidating the cognitive architecture of schizophrenia promises to advance understanding of the clinical and biological substrates of the illness. Traditional cross-sectional neuropsychological approaches differentiate impaired from normal cognitive abilities but are limited in their ability to determine latent substructure. The current study examined the latent architecture of abnormal cognition in schizophrenia via a systematic approach.

METHOD

Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were carried out on a large neuropsychological dataset including the Brief Assessment of Cognition in Schizophrenia, Continuous Performance Test, Wisconsin Card Sorting Test, Benton Judgment of Line Orientation Test, and Wechsler Abbreviated Scale of Intelligence matrix reasoning derived from 1012 English-speaking ethnic Chinese healthy controls and 707 schizophrenia cases recruited from in- and out-patient clinics.

RESULTS

An initial six-factor model fit cognitive data in healthy and schizophrenia subjects. Further modeling, which accounted for methodological variance between tests, resulted in a three-factor model of executive functioning, vigilance/speed of processing and memory that appeared to best discriminate schizophrenia cases from controls. Factor analytic-derived g estimands and conventionally calculated g showed similar case-control discrimination. However, agreement analysis suggested systematic differences between both g indices.

CONCLUSIONS

Factor structures derived in the current study were broadly similar to those reported previously. However, factor structures between schizophrenia subjects and healthy controls were different. Roles of factor analytic-derived g estimands and conventional composite score g were further discussed. Cognitive structures underlying cognitive deficits in schizophrenia may prove useful for interrogating biological substrates and enriching effect sizes for subsequent work.

Betula pendula leaves: polyphenolic characterization and potential innovative use in skin whitening products

The research of new tyrosinase inhibitors is currently important for the development of skin whitening agents; particularly, birch leaves extracts are included in many skin cosmetic products. In this study, the potential ability of Betula pendula leaves ethanolic extract (BE) was evaluated on mushroom tyrosinase activity. Results showed that BE was capable to inhibit dose-dependently l-DOPA oxidation catalyzed by tyrosinase. The inhibition kinetics, analyzed by Lineweaver-Burk plots, showed a noncompetitive inhibition of BE towards the enzyme, using l-DOPA as substrate. The inhibitory mechanism of BE as studied by spectrophotometric analysis, demonstrated its ability to chelate copper ion in the active site of tyrosinase. In addition, BE exhibited Fe(2+)-chelating ability (IC(50)=614.12±2.14 μg/mL), reducing power and radical-scavenging properties (IC(50)=137.22±1.98 μg/mL). These results suggest the usefulness of birch leaves extracts in cosmetic and pharmaceutical industries for their skin-whitening and antioxidant effects. Determination of the polyphenolic compounds in BE extracts was afterward achieved by means of high-performance liquid chromatography (HPLC) with photodiode array (PDA) and mass spectrometry (MS) detection. A total of 25 compounds were positively identified, through the complementary analytical information, and are reported in such a matrix for the first time. Knowledge on the qualitative composition and contents of these natural sources in fact represents mandatory information, for rational consumption and correlation of the beneficial effects to the specific amounts.

Control of inflammation and prophylaxis of endophthalmitis after cataract surgery: a multicenter study

PURPOSE

To compare two different postcataract surgery antibiotic/steroid therapeutic combinations, for clinical results as well as patient satisfaction.

METHODS

Prospective randomized clinical trial of patients with bilateral operative cataract. Postoperatively, for 15 days one eye was randomly assigned to therapy with the combination chloramphenicol 0.25%-betamethasone 0.13% gel three times a day (Group 1) and the other to the combination tobramycin 0.3%-dexamethasone 0.1% eyedrops four times a day (Group 2).

RESULTS

A total of 142 patients (284 eyes) completed the study. The authors could not detect any significant difference between Group 1 and Group 2 concerning preoperative evaluation, surgical procedure, and complications. Pertaining to the two therapeutic regimens, efficacy, side effects, and clinical findings such as uncorrected visual acuity, intraocular pressure, edema or hyperemia of eyelids and/or conjunctiva, conjunctival and/or ciliary vessels congestion, decreased corneal transparency, corneal edema, Descemet folds, anterior chamber Tyndall and depth, and posterior synechiae were also comparable. Postoperative subjective pain and dry eye sensation were comparable between the two groups, while the gel preparation elicited a significantly more pleasant sensation in the patients (p=0.04).

CONCLUSIONS

The motivation for use of a gel is to prolong the permanence of associated drugs on the ocular surface, increasing potency and decreasing concentration of the drug and rate of administration. This in order to improve compliance and decrease potential side effects. Chloramphenicol 0.25%-betamethasone 0.13% gel combination proved to have comparable efficacy, tolerance, and better acceptance by the patients than an aqueous tobramycin 0.3%-dexamethasone 0.1% preparation.

A pilot trial of topotecan administered orally in patients with advanced solid tumors expressing hypoxia inducible factor (HIF)- 1α

14103

Background: HIF-1 is a transcription factor frequently over-expressed in common human cancers that mediates a transcriptional program leading to tumor angiogenesis, survival and metastases. Previous studies have demonstrated that daily administration of topotecan (TPT), a topoisomerase I poison, inhibits HIF-1a expression, angiogenesis and tumor growth in human xenograft models. The primary aim of this study is to investigate whether TPT inhibits HIF-1a expression in human cancers. Methods: TPT was administered orally at 1.6 mg/m2 daily x 5 for 2 weeks, on a 28-day cycle, to adult patients with advanced solid tumors expressing HIF-1a in at least 10% of tumor cells, as assessed by IHC. Tumor biopsies are obtained before and at the end of treatment in cycle 2 and tested for HIF-1a protein expression by IHC and mRNA expression of HIF-1 target genes by real-time PCR. 18FDG-PET, to assess tumor metabolism, and DCE-MRI, to assess blood flow and permeability, were obtained at baseline, at the end of 2 weeks of therapy and then at the end of treatment on cycle 2. CT scans were performed before and after 2 cycles of therapy. Serial blood samples are obtained for PK analysis. Results: Seven patients, median age 54 (range 35–70), have been treated so far, with 6 patients being evaluable for the primary endpoint with paired tumor biopsies for analyses: melanoma (1), colorectal cancer (2), bladder (1), breast (1), ovarian (1). First two patients received the planned dose of 1.6 mg/m2; patient # 2 developed grade 3 neutropenia and grade 4 thrombocytopenia. As the objective was to develop a regimen for chronic dosing that was well tolerated and not directly cytotoxic, the protocol was amended to reduce the dose. Four patients have received a median of 2 cycles at 1.2 mg/m2, which has been well tolerated. A decrease of VEGF mRNA expression by more than 70% was observed in the 2 patients treated at 1.6 mg/m2 after 2 cycles of treatment. However, no consistent decrease of HIF-1a protein levels was detected in the corresponding tumor tissue. Enrollment continues. Conclusion: This is the first study aimed to validate inhibition of the HIF-1 signaling pathway in cancer patients. Funded in part by NCI Contract N01- CO-12400.

No significant financial relationships to disclose.

UVC inhibits HIF-1α protein translation by a DNA damage- and topoisomerase I-independent pathway

Hypoxia inducible factor 1 (HIF-1) is a key player in cancer progression and an attractive target for cancer therapy. Several small molecule inhibitors of HIF-1alpha also induce a DNA damage response. However, whether or not DNA damage is required for or associated with the inhibition of HIF-1alpha protein accumulation is poorly understood. In this report we investigated the effects of distinct DNA damaging conditions on the hypoxic induction of HIF-1alpha protein in cancer cell lines. We demonstrate that in addition to topotecan (TPT), a known inhibitor of HIF-1alpha, UVC, but not other DNA damaging agents (cisplatin, ionizing radiation and doxorubicin), inhibited HIF-1alpha protein accumulation in a dose-dependent, p53-independent fashion. Low doses UVC decreased HIF-1alpha translation without affecting global protein synthesis. Inhibition of HIF-1alpha by UVC required ongoing RNA transcription, but not DNA replication. Moreover, a functional ATR was required for the activation of DNA damage-dependent responses by both UVC and TPT, but was dispensable for the inhibition of HIF-1alpha protein. Notably, unlike TPT, inhibition of HIF-1alpha protein by UVC did not require topoisomerase I, suggesting a similar yet distinct mode of action. Our data reveal that UVC is a novel signal associated with inhibition of HIF-1alpha protein accumulation, and they uncouple the DNA damage-dependent signaling pathway exerted by UVC and TPT from HIF-1alpha inhibition.

Analysis of self-organized criticality in the Olami-Feder-Christensen model and in real earthquakes

We perform an analysis on the dissipative Olami-Feder-Christensen model on a small world topology considering avalanche size differences. We show that when criticality appears, the probability density functions (PDFs) for the avalanche size differences at different times have fat tails with a q-Gaussian shape. This behavior does not depend on the time interval adopted and is found also when considering energy differences between real earthquakes. Such a result can be analytically understood if the sizes (released energies) of the avalanches (earthquakes) have no correlations. Our findings support the hypothesis that a self-organized criticality mechanism with long-range interactions is at the origin of seismic events and indicate that it is not possible to predict the magnitude of the next earthquake knowing those of the previous ones.

Detecting complex network modularity by dynamical clustering

Based on cluster desynchronization properties of phase oscillators, we introduce an efficient method for the detection and identification of modules in complex networks. The performance of the algorithm is tested on computer generated and real-world networks whose modular structure is already known or has been studied by means of other methods. The algorithm attains a high level of precision, especially when the modular units are very mixed and hardly detectable by the other methods, with a computational effort O(KN) on a generic graph with N nodes and K links.

Activity of Berberis aetnensis root extracts on Candida strains

The antifungal activity of methanolic extract and alkaloidal fraction of Berberis aetnensis against Candida species was investigated. The crude extract was active against Candida species, this activity being higher than that of the alkaloidal fraction and berberine.

Efficacy and safety of bimatoprost in patients with uncontrolled glaucoma as alternative to filtration surgery

PURPOSE

To evaluate the efficacy and safety of bimatoprost 0.03% as an alternative to filtration surgery in patients with uncontrolled glaucoma.

DESIGN

Interventional study.

METHODS

A total of 83 consecutive patients (83 eyes) awaiting glaucoma surgery were enrolled in eight ophthalmic centers. Reasons for listing were inadequate intraocular pressure (IOP) control despite medical therapy and documented progression of visual field loss. All patients discontinued the previous treatment and were switched to bimatoprost 0.03% QD (one drop at 9 pm). The primary efficacy outcome was a 20% IOP reduction from baseline at each timepoint. IOP was measured at day 7, day 30, day 60, and day 90 of treatment; less than 20% IOP reduction was considered as a failure.

RESULTS

An IOP reduction of at least 20% was achieved in 74 patients (89.1%) after 7 days and in 64 patients (86.5%) after 30 days. Sixty-two patients (74.6%) maintained IOP readings 20% lower than baseline after 60 and 90 days. In these patients, visual field indices improved in 8 eyes (13%), and remained unchanged in 54 eyes (87%). Ocular side effects were conjunctival injection (15.6%), burning sensation (9.6%), foreign body sensation (4.8%), and eyelash growth (2.4%).

CONCLUSIONS

This preliminary study shows that bimatoprost 0.03% could represent a useful therapeutic tool that might defer filtration surgery.

Berberis aetnensis C. Presl. extracts: antimicrobial properties and interaction with ciprofloxacin

Previous research showed that berberine-containing Berberis species synthesise the substances 5'-methoxyhydnocarpin-D (5'-MHC-D) and pheophorbide a, which have no antimicrobial activity but inhibit the expression of multidrug resistant efflux pumps (MDRs) in Staphylococcus aureus and potentiate the action of berberine. The MDR pumps extrude synthetic and natural antimicrobials from bacterial cells. We searched for these compounds in Berberis aetnensis C. Presl. (Berberidaceae), an endemic plant of the volcano Mount Etna. This work confirms the presence of pheophorbide a and permits us to hypothesise the presence of 5'-MHC-D in leaf extracts. In fact, the activity of ciprofloxacin was improved when two chromatographic fractions isolated from leaf extracts were added. These results are indicative of the presence of MDR pump inhibitors. Moreover, crude extracts were tested on several micro-organisms and showed antimicrobial activity mainly against Gram-positive bacteria and yeasts.

Antibacterial activity of medicinal plant extracts against periodontopathic bacteria

This study was performed to evaluate the antibacterial activity of Althaea officinalis L. roots, Arnica montana L. flowers, Calendula officinalis L. flowers, Hamamelis virginiana L. leaves, Illicium verum Hook. fruits and Melissa officinalis L. leaves, against anaerobic and facultative aerobic periodontal bacteria: Porphyromonas gingivalis, Prevotella spp., Fusobacterium nucleatum, Capnocytophaga gingivalis, Veilonella parvula, Eikenella corrodens, Peptostreptococcus micros and Actinomyces odontolyticus. The methanol extracts of H. virginiana and A. montana and, to a lesser extent, A. officinalis were shown to possess an inhibiting activity (MIC < or = 2048 mg/L) against many of the species tested. In comparison, M. officinalis and C. officinalis extracts had a lower inhibiting activity (MIC > or = 2048 mg/L) against all the tested species with the exception of Prevotella sp. Illicium verum methanol extract was not very active though it had a particular good activity against E. corrodens. The results suggest the use of the alcohol extracts of H. virginiana, A. montana and A. officinalis for topical medications in periodontal prophylactics.

Hyperhomocysteinemia in menopausal hypertension: an added risk factor and a dangerous association for organ damage

Hyperhomocysteinemia is widely recognised as an emerging risk factor of endothelial dysfunction and vascular damage. In this study we wanted to verify if it, when associated to arterial hypertension--traditional risk factor--represents a higher added risk of organ damage during menopause, which is a condition connected to a higher incidence of cerebrovascular diseases. A survey of 30 postmenopausal women with similar characteristics (BMI, age, absence of relevant pathologies such as diabetes, metabolic disorders and absence of smoking) was selected (menopause had occurred from 12 to 16 months at the moment of observation). At the moment of the observation they had not gone through any continuous pharmacological therapy. They were subdivided into 3 groups: normotensive; hypertensive (with 2nd degree hypertension: mild to moderate) without organ damage; hypertensive with organ damage (TIA, ischaemic heart disease, etc.). The carotid IMT, measured with ultrasound method, was considered as an organ damage parameter. 43% of the patients had high levels of homocysteine (> 15 micromol/l), which are levels considered at risk in other surveys. The highest levels of homocysteine were recorded in hypertensive women with episodes of acute cerebrovascular damage (micromol/l = 24.3 +/- 8.9). In this group, a positive correlation (r = 0.7) was obtained between homocysteine levels and carotid IMT. The possible coexistence of hyperhomocysteinemia and arterial hypertension, even though without particularly high values for both of them, in menopause may represent a dangerous association responsible for a significant organ damage and, therefore, for acute cerebrovascular events.

[Usefulness of ultrasonography in the study of superficial lymph nodes. A case of cat scratch disease]

Ultrasonography is a wide spread, non-invasive and repeatable imaging methodology. It is able to evidence any type of lesion and to describe its extent, its site and its content. The ultrasound role in the diagnosis of a case of cat scratch disease in a 44 year old man is described. Symptoms included intermittent fever, pain and palpable tumefactions in right armpit and elbow. The patient underwent routine and lymphoadenopathy specific laboratory data. Ultrasound examination and echo-guided fine-needle biopsy of the evident lesions were performed. These exams, related to pathological clinical presentation, have shown a chronic granulomatous lymphadenopathy like cat scratch disease. This case provides further evidence that ultrasound procedures might play an important role in differential diagnosis of palpable lesions.

Non-Gaussian equilibrium in a long-range Hamiltonian system

We study the dynamics of a system of N classical spins with infinite-range interaction. We show that, if the thermodynamic limit is taken before the infinite-time limit, the system does not relax to the Boltzmann-Gibbs equilibrium, but exhibits different equilibrium properties, characterized by stable non-Gaussian velocity distributions, Lévy walks, and dynamical correlation in phase space.

Dangerous thrombophilic states and internal pathologies: 3 cases of thrombosis of the abdominal veins

Thrombosis of the abdominal veins is a rare clinical condition which can be assimilated with the more frequent localization of deep venous thrombosis of the lower limbs. In the last few years great attention has been paid to possible risk factors for thrombosis of the abdominal veins. Two risk factors that have been identified are the presence of internal diseases and congenital and/or acquired abnormalities of haemostasis. The authors describe 3 clinical cases (splenic and portal thrombosis due to congenital thrombophilia, Budd-Chiari syndrome, portal cavernoma consequent to ovarian neoplasia) with different etiopathogenesis to show how this apparently rare condition is today more frequently encountered and easier to recognize. In the presence of thrombosis of major venous structures the search and the identification of intrinsic internal risk factors and of congenital and acquired thrombophilic disorders remains of great importance. Screening for thrombophilia includes blood C and S proteins, AT III, homocysteine, Leiden mutation of the factor V gene, G20210A mutation of the prothrombin gene, antiphospholipid antibodies. The presence of one or more of these risk factors allows the identification of the cases of portal thrombosis (EHPVO) responsible for about 10% of all the cases of portal hypertension, without cirrhosis or other hepatic lesions. The primary diagnostic procedure however remains color-Doppler ultrasonography which represents the most simple and the cheapest diagnostic investigation for the study of the portal and suprahepatic vein system, but it's strictly operator dependent.

Genes for human general transcription initiation factors TFIIIB, TFIIIB-associated proteins, TFIIIC2 and PTF/SNAPC: functional and positional candidates for tumour predisposition or inherited genetic diseases?

TFIIIB, TFIIIC2, and PTF/SNAPC are heteromultimeric general transcription factors (GTFs) needed for expression of genes encoding small cytoplasmic (scRNAs) and small nuclear RNAs (snRNAs). Their activity is stimulated by viral oncogenes, such as SV40 large T antigen and Adenovirus E1A, and is repressed by specific transcription factors (STFs) acting as anti-oncogenes, such as p53 and pRb. GTFs role as final targets of critical signal transduction pathways, that control cell proliferation and differentiation, and their involvement in gene expression regulation suggest that the genes encoding them are potential proto-oncogenes or anti-oncogenes or may be otherwise involved in the pathogenesis of inherited genetic diseases. To test our hypothesis through the positional candidate gene approach, we have determined the physical localization in the human genome of the 11 genes, encoding the subunits of these GTFs, and of three genes for proteins associated with TFIIIB (GTF3BAPs). Our data, obtained by chromosomal in situ hybridization, radiation hybrids and somatic cell hybrids analysis, demonstrate that these genes are present in the human genome as single copy sequences and that some cluster to the same cytogenetic band, alone or in combination with class II GTFs. Intriguingly, some of them are localized within chromosomal regions where recurrent, cytogenetically detectable mutations are seen in specific neoplasias, such as neuroblastoma, uterine leyomioma, mucoepidermoid carcinoma of the salivary glands and hemangiopericytoma, or where mutations causing inherited genetic diseases map, such as Peutz-Jeghers syndrome. Their molecular function and genomic position make these GTF genes interesting candidates for causal involvement in oncogenesis or in the pathogenesis of inherited genetic diseases.

Trichilia roka Chiov. (Meliaceae): pharmacognostic researches

The dried aqueous extract of Trichilia roka Chiov. (Meliaceae) root was evaluated for its potential antipyretic activity on yeast-induced hyperthermia in rats. The drug showed a significant reduction of body temperature when administered orally at the doses of 0.25, 0.5 and 1.0 g/kg. The antipyretic activity of T. roka was compared to indomethacin treatment (50 mg/kg), used as a reference drug. The results of this study confirm the validity of traditional usage of T. roka as an antipyretic agent. Moreover, micromorphological investigations were carried out by scanning electron microscopy obtaining useful phytognostic elements for the correct identification of the drugs both in scraped and powdered forms because this is of great interest for quality control in basic research and drug production, especially for imported items and for raw material sold by traditional herborists.

Nepeta sibthorpii Bentham (Lamiaceae): micromorphological analysis of leaves and flowers

Nepeta sibthorpii Bentham (Lamiaceae) is an herbaceous aromatic plant, growing in dry, usually rocky areas of Southern Greece. In this paper, we report the study of micromorphological features of the flowers and leaves of Nepeta sibthorpii Bentham. The analysis by means of scanning electron microscopy has permitted to characterize both the covering trichomatous garment, abundantly present on the calyx and on the leaves, and the glandular hairs, distributed on the adaxial leaf surface and on the outer surfaces of calyx and corolla, showing also the peculiar features of the epidermal cells, all useful diagnostic elements for the identification of this medicinal plant.

Micromorphological investigations on Entada africana Guill. et Perr. (Mimosaceae)

Entada africana Guill. et Perr., known in Mali by the common local name 'Samanéré' in the Bambara language, is one of the traditional Malian medicines prescribed for many illnesses. In the present investigation, micromorphological studies were carried out by scanning electron microscopy on the roots and the leaves. The correct identification of the morphological characters of drugs is of great interest for quality control in basic research and drug production, especially for imported items and for raw materials sold by traditional herbalists.

Genomic localization of the human genes TAF1A, TAF1B and TAF1C, encoding TAF(I)48, TAF(I)63 and TAF(I)110 subunits of class I general transcription initiation factor SL1

Human SL1 is a general transcription initiation factor (GTF) essential for RNA polymerase I to start rRNA synthesis at class I promoters. It is comprised of the TATA box-binding protein (TBP) and three TBP-associated factors (TAF(I)48, TAF(I)63 and TAF(I)110). We have determined that the human genes TAF1A, TAF1B and TAF1C, encoding these three TAF(I) polypeptides, are localized at lq42, 2p25 and 16q24, respectively. All three genes are present as single copies in the human genome and map to different chromosomes, as shown by somatic cell hybrid panel and radiation hybrid panel analysis and FISH. Two of these genes, TAF1C and TAF1B, are transcribed into multiple RNAs, as determined through Northern analysis of mRNA from various human organs and cell lines. If translated into different polypeptides, this could result in production of variant isoforms of SL1 with different activation potentials.

The tryptophan catabolite picolinic acid selectively induces the chemokines macrophage inflammatory protein-1 alpha and -1 beta in macrophages

We previously found that the tryptophan catabolite picolinic acid (PA) is a costimulus for the activation of macrophage effector functions. In this study, we have investigated the ability of PA to modulate the expression of chemokines in macrophages. We demonstrate that PA is a potent activator of the inflammatory chemokines MIP (macrophage inflammatory protein)-1 alpha and MIP-1 beta (MIPs) mRNA expression in mouse macrophages in a dose- and time-dependent fashion and through a de novo protein synthesis-dependent process. The induction by PA occurred within 3 h of treatment and reached a peak in 12 h. The stimulatory effects of PA were selective for MIPs because other chemokines, including monocyte chemoattractant protein-1, RANTES, IFN-gamma-inducible protein-10, MIP-2, and macrophage-derived chemokine, were not induced under the same experimental conditions and were not an epiphenomenon of macrophage activation because IFN-gamma did not affect MIPs expression. Induction of both MIP-1 alpha and MIP-1 beta by PA was associated with transcriptional activation and mRNA stabilization, suggesting a dual molecular mechanism of control. Iron chelation could be involved in MIPs induction by PA because iron sulfate inhibited the process and the iron-chelating agent, desferrioxamine, induced MIPs expression. We propose the existence of a new pathway leading to inflammation initiated by tryptophan catabolism that can communicate with the immune system through the production of PA, followed by secretion of chemokines by macrophages. These results establish the importance of PA as an activator of macrophage proinflammatory functions, providing the first evidence that this molecule can be biologically active without the need for a costimulatory agent.

Blood pressure variations assessed by continuous 24-hour monitoring in menopausal and climacteric women

Changes in the metabolic hormonal balance during the climacteric and menopause, especially surgically induced menopause, increase the risk of acute cerebrocardiovascular complications. This major risk may be linked to changes in blood pressure. In this study we performed twenty-four ambulatory blood pressure monitoring in climacteric (C), menopausal (PM), and surgically induced menopausal women (SM) to determine mean diurnal and nocturnal systodiastolic levels and percentage peaks, as variations in the pressure profile may be linked to organ damage. Our results showed that the entire series presented mainly diastolic increments (mDBP: HPM = 104.4 +/- 5.1; HSM = 106.3 +/- 2.9; HC = 100.2 +/- 3.1), and that this rise was greater in surgically induced menopausal women. In addition, these subjects presented the highest diastolic and systolic pressure peaks (HSM 37/42 versus HPM 35/36 and HC 29/31) also during the night (nocturnal peak: HSM 15/19 versus HPM 10/12 and HC 5/15). Non dippers seem more exposed to cerebrocardiovascular disease. Our results revealed that climacteric patients affected by arterial hypertension (mSBP = 162.2 +/- 4.1; mDBP = 100.2 +/- 3.1; 24 h systolic peak % = 24, diastolic peak % = 24) during the climacteric presented the same levels as observed in conclaimed menopause (mSBP 165.2 +/- 5.5; mDBP = 104.2 +/- 5.1; 24 h systolic peak % = 28, diastolic peak % = 29). Therefore, 24 h blood pressure monitoring is able to show that the pressure changes in hypertensive climacteric and menopausal women and could detect women who are at a greater risk of organ damage.

Genomics of the human genes encoding four TAFII subunits of TFIID, the three subunits of TFIIA, as well as CDK8 and SURB7

By in situ chromosomal hybridization, and by somatic cell and radiation hybrid analysis, we have determined the genomic position of the human genes encoding four TAFII subunits of TFIID (TAFII150, TAFII105, TAFII68, TAFII18), the three subunits of TFIIA (TFIIA35 and TFIIA19, both encoded by the same gene, and TFIIA12), CDK8, and SURB7. All of these proteins are bona fide components of human class II holoenzymes as well as targets of signal transduction pathways that regulate genome expression. The genes encoding them are present in the human genome in a single copy and are localized at 8q23, 18q11.2, 17q11.1-11.2, 1p21, 14q31, 15q21-23, 13q12, and 12p12, respectively. We have mapped all of them to chromosomal regions where hereditary genetic diseases have been localized or which are involved in malignancies, which makes them potential candidates for a causal involvement in these phenotypes.

[Tophaceous gout in plurimetabolic syndrome]

Aim of this paper is to describe and discuss, on the basis of the available current literature, the case of a female patient affected by a tophaceous gout associated with plurimetabolic syndrome. Hyperuricemia and gout may be seen today in all the populations of developed countries, with increasing frequency on the last fifty years. Increased production or reduced urinary excretion of uric acid (and hypoxanthine and xanthine) are the most important pathogenetic mechanisms of primary or secondary hyperuricemia. Gout is an acute rheumatic disorder (characterized by a limited range of manifestations) which occurs in humans in connection with deposition of crystals of monosodium urate (the final product of purine metabolism) in the articular and soft periarticular tissues. Hyperuricemia and/or gout are often associated with hyperinsulinemia, obesity, diabetes mellitus, hyperlipemia, hypertension and atherosclerosis to form the syndrome called "Plurimetabolic syndrome" or "Syndrome X". Here we report the clinical case of a 64-year-old female patient who had android obesity, type 2 diabetes mellitus, hypertension, dyslipidemia and hyperuricemia and had been suffering (over many years) from intermittent episodes of severe pain and inflammatory joint swelling (first metacarpo- and metatarso-phalangeal joints) with development of pronounced multiple tophi in bone articular and soft periarticular tissues. Hyperuricemia and acute episodes had never been treated with anti-hyperuricemic drugs because gouty arthritis had never been diagnosed. This severe tophaceous gout associated to multiple metabolic disorders prompted us to present knowledge on gout and to focus on the interrelationships between hyperuricemia and/or gout and plurimetabolic syndrome, important risk factors for coronary heart disease.

Oral toxicity of bis(2-ethylhexyl) phthalate during pregnancy and suckling in the Long-Evans rat

Bis(2-ethylhexyl) phthalate (DEHP) is a compound widely used in plastics technology to impart flexibility to rigid polymers. We sought to determine whether the oral exposure of female rats to DEHP during gestation and suckling produces alterations in the litter. Female rats were exposed to different concentrations of DEHP suspended in drinking water (32.5 and 325 microl/litre) from day 1 of pregnancy to day 21 after delivery. Pup body weight gain and kidney, liver and testes weight was measured at different times (21, 28, 35, 42 and 56 days) after birth. Plasma concentrations of DEHP and histopathological alterations in kidneys, liver and testes were also studied. In addition, the ability of female pups (1 month of age) to perform a learned avoidance test, the 'beam walking' test, was evaluated. Perinatal exposure to DEHP produced no statistically significant changes in the body weight gain of offspring. Conversely, it produced a significant decrease in kidney and testes relative weight (organ/body weight) with a significant increase in relative liver weight. Signs of histological damage in kidneys, liver, and particularly testes, were observed. Pups exposed perinatally to the highest concentration of DEHP elicited a significant increase in the time necessary to perform the beam walking test.

Genomics and transcription analysis of human TFIID

TFIID, a multisubunit protein comprised of TBP (TATA box-binding protein) and TAF(II)s (TBP-associated factors), has a central role in transcription initiation at class II promoters. TAF(II)s role as mediators of regulatory transcription factors, such as pRb and p53, and their involvement in signal transduction pathways suggest that some may participate in the control of cell proliferation and differentiation: therefore, they could be considered potential protooncogenes or antioncogenes. With the aim of starting to analyse these potential roles, we have determined the genomic position of nine human TAF(II) genes (TAF[II]250, TAF[II]135, TAF[II]100, TAF[II]80, TAF[II]55, TAF[II]43, TAF[II]31, TAF[II]28, TAF[II]20/15) and of two previously unknown sequences related to TAF(II)250 and TAF(II)31, respectively. Except for those encoding TAF(II)250 and TAF(II)31, these genes are present in a single copy and, with the exclusion of those for TAF(II)43 and TAF(II)28 (both at 6p21), are localized in different segments of the genome. Indeed, six of them map to a chromosomal region commonly altered in specific neoplasias, which defines them as candidates for involvement in oncogenesis. Our experiments also demonstrate that TAF(II) transcripts are synthesized ubiquitously, mostly at low levels similar to those of TBP. Interestingly, the amount of the major mRNA species detected by TAF(II)20/15 cDNA is higher, which suggests that the polypeptide it encodes may also perform functions independently of TFIID. TAF(II) isoforms, indicated by additional bands on Northern blots, may play a role in modulation of TFIID function. These data will be useful for analysing variations of TAF(II) mRNA phenotype during cell proliferation, differentiation and development, both normal and pathological.

Compositional mapping of mouse chromosomes and identification of the gene-rich regions

The mouse genome is a mosaic of isochores, consisting of long (> 300 kb), compositionally homogeneous DNA segments that can be divided into two GC-poor families, L1 and L2, representing 56% of the genome, and two GC-rich families, H1 and H2, representing 26% and 7% of the genome, respectively, the remaining 11% being formed by satellite and ribosomal DNAs. (GC is the molar fraction of guanine + cytosine in DNA.) The mouse genome differs from the human genome (which is representative of most mammalian genomes) because it shows a narrower compositional spectrum of isochores and it has a karyotype formed exclusively by acrocentric chromosomes. The chromosomal distribution of the four isochore families, as investigated here by in situ hybridization of single-copy sequences from compositional DNA fractions, has shown that G(lemsa) bands are essentially composed of GC-poor isochores, whereas R(everse) bands comprise three subsets of bands: R' bands, containing GC-poor isochores and GC-rich isochores of the H1 family, and T and T' bands, containing all H2 isochores (in addition to other isochores), the former containing a higher proportion of H2 isochores than the latter. Mouse T and T' bands are generally syntenic with, and are compositionally related to, human T and T' bands and have the highest gene concentrations. These findings indicate that the distribution of isochore families and genes in chromosomal bands is basically similar in mouse and in human genomes, in spite of their remarkable differences and their extremely large phylogenetic distance.

In vitro antimicrobial activity of Pistacia lentiscus L. extracts: preliminary report

The in vitro antimicrobial activity of Pistacia lentiscus L. extracts was determined. Pistacia lentiscus L. extracts were tested on bacteria (Sarcina lutea, Staphylococcus aureus and Escherichia coli) and fungi (Candida albicans, Candida parapsilosis, Torulopsis glabrata and Cryptococcus neoformans). Of the different plant extractions, decoctions showed the best antibacterial activity, but the activity against fungal cells appears to be much more interesting.

Effect of 2,6-diisopropylphenol on the delayed hippocampal cell loss following transient forebrain ischemia in the gerbil

We examined the protective activity of 2,6-diisopropylphenol on mortality and delayed hippocampal cell death induced by transient cerebral ischemia in the gerbil. Forebrain ischemia was produced by bilaterally occluding the common carotid arteries for 10 minutes; then the blood supply to the brain was restored. The number of survivors was counted for 8 days, and the histopathological damage in the CA1 region of the hippocampus was scored according to the semiquantitative scale of Rudolphi and Colleagues. When intraperitoneally injected immediately after the ischemic attack, 2,6-diisopropylphenol (25, 50, 100 mg kg-1) produced no significant reduction in the rate of mortality in comparison with its vehicle. However, the survivors that had received the compound at the dose of 50 and 100 mg kg-1 elicited a significant increase in the number of viable pyramidal cells in the CA1 hippocampal region. Moreover, we obtained similar results by injecting the compound 30 minutes after the release of the carotid artery occlusion. These results suggest that 2,6-diisopropylphenol, although it does not show any capability of improving the rate of survival, it elicits protective properties against the transient forebrain ischemia-induced delayed hippocampal neuronal death.

Genomic localization of the human gene encoding Dr1, a negative modulator of transcription of class II and class III genes

Dr1 is a nuclear protein of 19 kDa that exists in the nucleoplasm as a homotetramer. By binding to TBP (the DNA-binding subunit of TFIID, and also a subunit of SL1 and TFIIIB), the protein blocks class II and class III preinitiation complex assembly, thus repressing the activity of the corresponding promoters. Since transcription of class I genes is unaffected by Dr1. it has been proposed that the protein may coordinate the expression of class I, class II and class III genes. By somatic cell genetics and fluorescence in situ hybridization, we have localized the gene (DR1), present in the genome of higher eukaryotes as a single copy, to human chromosome region 1p21-->p13. The nucleotide sequence conservation of the coding segment of the gene, as determined by Noah's ark blot analysis, and its ubiquitous transcription suggest that Dr1 has an important biological role, which could be related to the negative control of cell proliferation.

Leaf extracts of some Cordia species: analgesic and anti-inflammatory activities as well as their chromatographic analysis

Leaf preparations of several species of Cordia are used in traditional medicine as remedies for osteoarticular diseases. The analgesic, anti-inflammatory and anti-arthritic activities in the rat of different extracts of C. francisci, C. martinicensis, C. myxa, C. serratifolia and C. ulmifolia leaves were studied. The results obtained showed that the petroleum ether and alcoholic extracts especially of C. francisci, C. myxa and C. serratifolia leaves have a significant analgesic, anti-inflammatory and anti-arthritic activity in the rat. The flavonoids and phenolic derivative content of the five species of genus Cordia leaves was investigated by TLC and determined by reversed-phase HPLC with an acetonitrile/water/acetic acid buffer solvent gradient. UV detection was carried out at 255 and 280 nm. Four flavonoid glycosides, robinin, rutin, datiscoside and hesperidin, one flavonoid aglycone, dihydrorobinetin, two phenolic derivatives, chlorogenic and caffeic acid, were evidenced and determined.